Electric warp stop motion



Dec. 1, 1936. R; e. TURNER ELECTRIC WARP STOP MOTION Filed July 5, 1955Inventor rfleai Turner orneya 1 Richard wen i A? Patented Dec. 1, 1936UNITED STATES PATENT OFFICE Richard Greenleaf Turner, Worcester, Mass.,asslgnor to Crompton & Knowles Loom Works, Worcester, Mass., acorporation of Massachusetts Application July 5, 1935, Serial No. 29,769

12 Claims.

This invention relates to improvements in warp stop motions andparticularly the means for finding the fallen drop wire on electricalwarp stop motions.

Electrical warp stop motions customarily employ a relatively large groupof light thin drop wires each effective when fallen to close a circuitincluding a loom stopping electromagnetic device. It is a matter ofpractical difiiculty to 10 determine the location of the fallen dropwire, particularly in electrical motions where there is ordinarily nomoving part to cooperate with the fallen drop wire. Warp stop motions ofelectrical type customarily employ contact bars includa ing twoelectrodes insulated from each other and arranged to be electricallyconnected by the fallen drop wire to close a circuit. It is an importantobject of my present invention to provide means dependent upon the heatdeveloped by passage of current through the fallen drop wire to indicatethe location of the latter.

In order to make effective use of the heat principle I employ a dropwire made of two component parts having different co-eificients ofexpansion. I may, for instance, make the drop wire out of sheet materialone side of which is formed of sheet brass while the other side isformed of sheet steel, the two parts being secured together in anyapproved manner so that in effect these two parts 3 form a single dropwire. The wire thus formed will tend to curve when heated, the greaterexpansion of one metal deforming or bending the drop wire to give avisual indication of its posi- I tion.

In the specific form set forth hereinafter I employ a drop wire of thetype which has gone into general use with a well-known form ofelectrical warp stop motion set forth more particularly in patent toPayne No. 1,852,024. The drop wire for that type of warp stop motion hasin the upper part thereof a slot to receive a contact bar whichcooperates with a pair of cam shaped lobes arranged to connectelectrically the two electrodes of the contact bar. The current flowsfrom the lobes partly through the upper and partly through the lowerpart of the drop wire, tending to heat and therefore curve aconsiderable length of the wire.

In order to prevent burning of contact bars and drop wires it iscustomary in warp stop motions to break the circuit by the stopping ofthe loom. Any heating which might result in the drop wire in the shortinterval between the falling of the before the weaver has an opportunityto visit the loom, and it is a further object of my present invention toprovide a manually controlled heating circuit to include the fallen dropwire. By means of this circuit the weaver can establish a currentthrough the fallen drop wire and by watching the bank of drop wires willbe able to detect the lateral movement or disturbance in drop wirescaused by the curvature of the one which is down. As amatter ofpractical convenience the manually controlled circuit omits theelectro-magnetic device so that a repeated indication is eliminated.This latter feature also results in removing the resistance of theelectromagnetic device from the heating circuit with resultant increasedcurrent which will cause the fallen drop wire to bend in a minimum oftime.

With these and other objects in view which will appear as thedescription proceeds, my invention resides in the combination and.arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawing, wherein a convenient embodiment of myinvention is set forth,

Fig. l is a rear elevation of a portion of a warp stop motion havingmydrop wires applied, and showing one of the drop wires curved by heat toindicate its location,

Fig. 2 is an enlarged section on line 22, Fig. 1, showing the drop-wirein fallen position,

Fig. 3 is an end elevation taken in the direction of arrow 3, Fig. 2,showing the drop wire fallen and straight before the heating circuit hasbeen manually closed in full lines and indicating in dotted lines thecurvature resulting in the drop Wire when the heating circuit is closed,and

Fig. 4 is a diagrammatic view of the electric circuits which I mayemploy.

Referring to the drawing, I have indicated a contact bar In having anouter electrode II with a longitudinal rib I2 and bent along its top andbottom edges at l3. Located within the outlines of electrode II isasecond electrode l4 insulated therefrom and having a contacting surfaceI5 which is horizontally opposite] the rib l2. The 45 bar I0 may besupported by a holder l6 which serves also to support separator bars II.The inner electrode may project as at I8 to have contact with a wire l9electrically connected to means for stopping the loom when the twoelectrodes are in electrical connection.

The drop wire 25 may be of the form shown in Fig. 2 and has an upperslot 26' through which the contact bar passes and into which lobesproject. The lower part of the drop wire may have an open slot 28 bymeans of which the wire is dropped on a warp thread W extending acrossand positioned by the separator bars Normally, the drop wire will be inelevated position so that neither of the lobes 21 is in operativerelation with respect to the electrode, but when a warp thread breaksits drop wire falls to the position shown. in Fig. 2', and the camminginteraction between the rib 2 and one of the lobes moves the other lobeagainst the the insulated electrode. Thereupon current flows from one ofthe electrodes through that part of the wire surrounding the slot 26 'tothe other electrode to effect loom stoppage. The matter thus fardescribed may be substantially the same as set forth in the aforesaidpatent to Payne.

As already indicated the difficulty of locating the fallen drop wire isconsiderably increased when there are several banks of drop wiressimilar to those set forth in Fig. 2, and the difllculty is furtherincreased by the varied positions of the drop wires when the loom isequipped with a number of harness frames which may be in a variety ofvertical positions when the loom stops. In order to locatelthe drop wireI propose to make the same of two dissimilar metals one of which has aco-efiicient of expansion considerably greater than the other. As shownin Fig. 3, for instance, the drop wire may be made of a thin'strip ofsteel 30 secured to a second strip 3| which may be formed of brass orcopper. These two sheets are fused or otherwise secured together and aresimilar to commercial products employed in the manufacture ofthermostats.

The drop wires will ordinarily be in close relationship as suggested inthe greater part of Fig. 1 and when current flows from one lobe 21 tothe other it must pass through both metallic parts of the drop wire,resulting in an unequal expansion which bows the drop wire, as shown inFig. 1. Ordinarily a drop wire will be straight as shown in full linesin Fig. 3, but when current flows therethrough it will curve to thedotted line position and serve to spread or disturb adjacent drop wiresas suggested in Fig. 1, thereby indicating the location of the brokenwarp thread.

A weaver ordinarily takes care of a group of looms and may not be near aloom when it is stopped by a warp fault, and furthermore, it isdesirable to break the circuit through the warp stop motion as soon asthe loom stops to prevent burning of the drop. wires and to reduce firehazard. In order to take these conditions into account I provideelectric circuits shown in Fig. 4 suitable for stopping the. loom andalso for enabling the weaver to reestablish a circuit through the fallendrop wire. The shipper handle 40 of the loom is indicated in full linesin the running position and when in this position is in electric contactwith'a contact 4| set forth diagrammatically in Fig. 4. A manuallyoperable switch S comprises a vertical stem 45 urged upwardly by acompression spring 46 and passing through a housing indicateddiagrammatically at 41. The spring coacts with part of the housing tourge the stemupwardly so that the bridge or cross bar 48 moving with thestem will normally have yielding contact with a pair of upper electrodes49 and 50, respectively. There are two other electrodes 5| and 52located beneath the first described pair also capable of electricalconnection by means of bridge 48.

When the loom is running normally the contacts 49 and 50 will beconnected by the bridge and upon occurrence of a warp fault current willflow in the following stopping circuit: ground G, wire 60, shipperhandle 40, contact 4|, wire 6|, electro-magnetic device 62, which whenenergized effects loom stoppage, wire 63, source of electric power, suchas a transformer 64, wire l9, insulated electrode [4, the fallen dropwire 25, inclosing electrode wire 65, electrode 49, bridge 48, electrode50, and wire 66 to the ground. Closure of this circuit will operate tomove the shipper handle from the full to the dotted line position shownin Fig. 4 when the loom stops, thereby breaking the circuit with noappreciable heating of the drop wire.

When the weaver arrives at the loom the stem 45 may be moved downwardlymanually so that the bridge assumes the dotted line position shown inFig. 4, electrically connecting the electrodes 5| and 5 2, whereuponcurrent will flow in the following heating circuit: transformer 64, wire|9, insulated electrode 14, the fallen drop wire 25, electrode wire 65,wire 10, electrode 5|, bridge 48, electrode 52, wire 61, and wire 63back to the transformer. is maintained closed as long as needed to causethe requisite heating of the fallen-wire.

The switch S is conveniently located in such a position that when beingpressed the weaver will have an opportunity to watch the drop wires andnotice any jarring or disturbance which results from the bending of thefallen drop wire as the latter tends to assume the position indicated indotted lines in Fig. 3. When the location of the warp fault is found theswitch S is released and the spring .around the stem reestablishescontact between electrodes 49 and 50. The second or heating circuittraced hereinbes fore does not include the electro-magnetic device, thelatter being purposely eliminated so that the resistance of the circuitis a minimum to permit heating of the drop wire in the shortest timepossible. Upon cooling a fallen drop wire will. assume its normally fiator straight position.

From the foregoing it will be seen that I have provided a simple form ofdrop wire for electrical warp stop motions so constructed that currentpassing through it will cause a change in the form thereof of sufficientextent to spread or disturb adjacent drop wires to indicate the locationof the broken warp thread. It will further be seen that I have provideda heating circuit supplementary to the normal stopping circuit andmanually operable by the weaver after the stopping circuit has beenbroken due to loom stoppage. While I have suggested two different metalsof which the drop wire can be made, yet I do not wish to be limited tothese metals inasmuch as the principles set forth herein dependgenerally for their operation upon deformation of a fallen drop wire toindicate the location of the warp fault.

Having thus described my invention it will be seen that changes andmodifications may be made therein by those skilled in the art withoutdeparting from the spirit and scope of the invention and I do not wishto be limited to the details herein disclosed, but what I claim is:

1. In an electric warp stop motion, a contact bar comprising twoelectrodes insulated from each other, and a drop wire capable of fallinginto contact with both electrodes upon occurrence of a warp fault andformed of two materials having difierent co-efiicients of expansion,

This heating circuit to cause a deformation in the drop wire whencurrent passes therethrough to indicate its location.

2. In an electric warp stop motion, a contact bar comprising twoelectrodes insulated from each other, and a drop wire capable of fallinginto contacting relation with respect to each electrode, the drop wirebeing formed of two substantially similar sheets secured together andeach sheet having a co-efficient of expansion different from that of theother sheet, whereby current flowing through the drop wire will heat anddeform the latter to give visual indication of its location.

3. In an electric warp stop motion, a contact bar comprising a pair ofinsulated electrodes, a drop wire normally out of electrical engagementwith the electrodes but capable of falling to a position to connect theelectrodes when the corresponding warp thread is broken, and meansincluding a manually operative switch to establish a circuit includingsaid switch and electrodes and the drop wire when fallen to cause acurrent to flow through the latter and heat the same, said drop wireconstructed to undergo a change in the form thereof when heated by acurrent passing therethrough to indicate its location.

4. In an electrical warp stop motion, a contact bar comprising twoelectrodes insulated from each other, and a drop wire effective when thecorresponding warp thread therefor is broken to move to contactingposition with respect to the electrodes and thereby be rendered capableof having a current of electricity pass therethrough, the drop wireconstructed of materials having dissimilar co-eflicients of expansion toeffect a deformation in the drop wire when heated to indicate itslocation.

5. In a loom, a warp stop motion contact bar comprising two insulatedelectrodes, a part to be moved from running to stopping position whenthe loom is stopped, a drop wire capable when heated of changing itsform to indicate its location, means including the drop wire when incontact with the electrodes and also the electrodes defining a stoppingcircuit which is broken when said part moves from running to stoppingposition, a manually operated switch, and other means including saidswitch and fallen drop wire and constituting a heating circuit effectivewhen closed to cause current to pass through said fallen drop wire andthereby heat the drop wire.

6. In a loom, a warp stop motion contact bar, a drop wire normally inraised position and capable when in fallen position of having anelectric current pass therethrough by engagement with the contact bar,said drop wire effective when heated to undergo a change in form thereofto indicate its location, means including the fallen drop wireconstituting a stopping circuit to effect loom stoppa e, a manuallyclosable switch, and other means including the switch and fallen dropwire constituting a heating circuit effective when closed by the switchto cause current to pass through the drop wire and heat the same toeffect a. change of form therein.

7. In an electrical warp stop motion, a drop wire having a slot formedtherein, a pair of lobes extending into the slot, a contact bar passingthrough the slot and having two electrodes insulated from each other,the lobes effective when the drop wire is fallen to connect theelectrodes electrically and permit passage of current from theelectrodes through the drop wire, said drop wire formed of two materialshaving dissimilar co-eificients of expansion effective to subject thedrop wire to a change in form when heated by current passingtherethrough.

8. In an electrical warp stop motion, a drop wire having a slot therein,a contact bar passing through the slot and comprising two insulatedelectrodes, means to cause a drop wire when fallen to move intoelectrical connection with both electrodes to permit the current to flowthrough the drop wire, said drop wireformed of two materials havingdissimilar co-efiicients of expansion rendering the drop wire capable ofundergoing an alteration in its form when heated by an electric currentflowing therethrough.

9. In a loom, a warp stop motion contact bar comprising two electrodesinsulated from each other, a drop wire effective when in fallen positionto connect the electrodes electrically and be capable of transmitting anelectric current from one electrode to the other, said drop wireeffective when heated to undergo a change in form thereof, a stoppingcircuit including the fallen drop wire and electrodes to effect loomstoppage, a normally open switch, and other means including the fallendrop wire and electrodes constituting a heating circuit to be estab'lished when the switch is closed for the purposes of causing current toflow through the drop wire and heat the same.

10. An electric warp stop motion drop wire formed of two parallel stripsof metal secured to each other throughout their length and havingdissimilar co-eflicients of expansion.

11. An electrical warp stop motion drop wire formed of two similarsheets of material secured to each other, each sheet having aco-efiicient of expansion different from that of the other sheet.

12. An electrical warp stop motion drop wire having a slot therein intowhich project lobes at points intermediate the ends of the slot, saiddrop wire formed of parallel strips of metal secured to each otherthroughout their length and having dissimilar co-eflicients of expansionand capable of conducting current from the lobe toward each end of theslot.

RICHARD GREENLEAF TURNER.

